Composite polishing pad

ABSTRACT

An abrasive article referred to as composite polishing pad (CPP) includes a plurality of fixed abrasive elements or a plurality of chemical mechanical polishing (CMP) pads attached to a plurality of pressure pads suspended to flexible structures capable to follow the wafer topography. A plurality of stems with dimpled ends act on the pressure pads to generate desired pressure acting on the wafer. The stems are attached to a spring arrangement capable of substantial vertical deflection under a desired load. In one embodiment a plurality of pressure pads suspended to a plurality of stems by revolute joints. The stems are attached to a spring arrangement capable of substantial vertical deflection under a desired load. In another embodiment, a plurality of pressure pads are attached to a plurality of stems suspended to a series of springs capable of substantial vertical deflection under a desired load.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefits of the filing date of U.S.Provisional Patent Application Ser. No. 61/315,191 filed Mar. 18, 2010,which is entitled “Composite Polishing Pad”, U.S. Provisional PatentApplication Ser. No. 61/315,210 filed Mar. 18, 2010, which is entitled“Method to enhance polishing performance of abrasive charged structuredpolymer substrates” and U.S. Provisional Patent Application Ser. No.61/315,237 filed Mar. 18, 2010, which is entitled “Method to enhancepolishing performance of abrasive charged polymer substrates” all ofwhich are hereby incorporated herein in their entirety by reference.

FIELD OF THE INVENTION

The present invention is directed to an abrasive article including aplurality of abrasive element independently attached to gimbalstructures.

BACKGROUND OF THE INVENTION

The invention relates to modifying the rigid substrate of a fixedabrasive article or a chemical mechanical pad used in semiconductorwafer polishing.

Chemical mechanical polishing (CMP) processes are used n semiconductorwafer fabrication to polish and planarize a semiconductor wafer. CMPprocesses involve placing an abrasive between a relatively stiff pad anda semi-conductor wafer and moving the pad and the semiconductorrelatively to each of the to modify the surface of the wafer. Theabrasives used in CMP process can in the form of a slurry or fixedabrasive particles, or a fixed abrasive element.

CMP processes attempt to remove material selectively from high locationi.e. features having dimensions on the scale of those features commonlyproduced by photolithography, to planarize the wafer surface. CMPprocesses also attempt to remove material uniformly on the scale of thesemiconductor wafer so that each die on the wafer is planarized to thesame degree in an equivalent amount of time. The rate of planarizationfor each die is preferably constant over the entire wafer. It isdifficult to achieve both these objective simultaneously becausesemiconductor wafers are often curved and warped. Semiconductor waferspresent a topography with roughness, short and long range waviness inthe radial and circumferential directions. At the microscopic level asemiconductor wafer is analogous to a potato ship. In addition some ofthe semiconductor wafers include numerous step height variations andprotrusions, which are produced during the fabrication sequence of anintegrated circuit on a wafer. These height variations and the wafertopography of the semiconductor wafer can interfere with the uniformityof the polishing process such that some regions of the wafer become overpolished while other regions remain under polished.

In modern integrated circuit fabrication, layers of material are appliedto embedded structures previously formed on semiconductor wafers. CMP isan abrasive process used to remove these layers and polish the surfaceof a wafer flat to achieve the desired structure. CMP may be performedon both oxides and metals and generally involves the use of chemicalslurries applied via a polishing pad that is moved relative to the wafer(e.g., the pad may rotate circularly relative to the wafer). Theresulting smooth, flat surface is necessary to maintain thephotolithographic depth of focus for subsequent steps and to ensure thatthe metal interconnects are not deformed over contour steps.

The planarization/polishing performance of a pad/slurry combination isimpacted by, among other things, the mechanical properties and slurrydistribution ability of the polishing pad. Typically, hard (i.e., stiff)pads provide good planarization, but are associated with poor with-inwafer non-uniformity (WIWNU) film removal. Soft (i.e., flexible) pads,on the other hand, provide polishing with good WIWNU, but poorplanarization. In conventional CMP systems, therefore, harder pads areoften placed on top of softer pads to improve WIWNU. Nevertheless, thisapproach tends to degrade planarization performance when compared to useof a hard pad alone.

It is therefore the case that designing CMP polishing pads requires atrade-off between WIWNU and planarization characteristics of the pads.This trade-off has led to the development of polishing pads acceptablefor processing dielectric layers (such as silicon dioxide) and metalssuch as tungsten (which is used for via interconnects in subtractiveprocessing schemes). In copper processing, however, WIWNU directlyimpacts over-polishing (i.e., the time between complete removal ofcopper on any one area versus complete removal from across an entirewafer surface) and, hence, metal loss and, similarly, planarization asexpressed by metal loss. This leads to variability in the metalremaining in the interconnect structures and impacts performance of theintegrated circuit. It is therefore necessary that both planarity andWIWNU characteristics of a pad be optimized for best copper processperformance.

Some of the above-described concepts can be illustrated graphically.FIG. 1 illustrates the surface of a post-CMP wafer 100 with copperinterconnects 101 defined in a low-K dielectric layer 103. Stressinduced cracking damage 102 is seen on the surface of the dielectriclayer 103, as a result of using a conventional polishing pad. Dishingand erosion increase with over-polishing, hence there is a need tominimize over-polishing of copper wafers.

CMP processes that employ slurry have been modified in an effort toovercome the problem of non-uniform polishing as summarized above. Asproposed by Goetz (2008) a composite polishing pad that includes a firstelastic material carrying fixed abrasive tiles. The elastic side of thefirst elastic layer is attached to a second stiff layer. Fixed abrasivepolishing do not rely on the transport of loose abrasive particles overthe surface of the pad to effect polishing. The abrasive tiles includeabrasive particles disposed in a binder and bonded to the backing, whichforms a relatively high modulus fixed abrasive element. The proposedapproach by Goetz suffers from a lack of ability to follow thetopography of the semiconductor wafer to cause uniform cutting pressureduring the polishing process.

Pressure sensing elements 300 are also connected to a pressure controlmechanism to effect an appropriate pressure profile during polishing isshown in FIG. 3 by Baraj et al. (2009). Monitoring the pressuresdetected by the pressure sensing elements 301 and comparing thatinformation to an established pressure model apply a predeterminedpressure profile. Differences between the actual pressures and thepressure model may then be used to alter the polishing operations toaffect the desired pressure profile. This approach is effective for longrange waviness. The size of the sensing device is substantially largerthan the die size leading to an average pressure detection not aninstantaneous pressure detection as required to compensate for dishingand over polishing for small wafer features. In addition short rangewavelength pressure fluctuations cannot be readily detected.

SUMMARY OF THE INVENTION

The proposed solution suspends each polishing element to comply with thesemiconductor topography in a planar fashion while applying a desiredload and pressure independently of the location on the wafer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the surface of a post-CMP wafer.

FIG. 2 is a cross section view of a wafer is a schematic cross sectionalview of a portion of an abrasive article reported in prior art.

FIG. 3 is a cross section view of a wafer is a schematic cross sectionalview of a portion of an abrasive article reported in prior art.

FIG. 4 is a cross section view of an example embodiment of the presentinvention.

FIG. 5 is an exploded view a single component forming the compositeuniversal polishing pad (CPP), according to an example embodiment.

FIG. 6 gives a view of an assembled CPP, according to an exampleembodiment.

FIG. 7 gives an exploded view of the layers forming a CPP, according toan example embodiment.

FIG. 8 gives a close up view of the preload structure and thegimaballing structure where a polishing pad attached, according to anexample embodiment.

FIG. 9 gives a close up view of the out of plane (curvilinear) springsforming the gimbal structure, according to an example embodiment.

FIG. 10 gives a close up of the preload structure with the preload stemsupported by a series of out of plane springs, according to an exampleembodiment.

FIG. 11 gives a concept of using a continuous polishing pad, accordingto an example embodiment.

FIG. 12 gives a view a single component forming a CPP with a continuouspolishing pad, according to an example embodiment.

FIG. 13 gives a view of a single component forming a CPP with acontinuous polishing pad, according to an example embodiment.

FIG. 14 gives an exploded view of a single component forming a CPP witha continuous polishing pad, according to an example embodiment.

FIG. 15 gives a cross section of a CPP with preload stems with apolishing pad attached to the end of the preload stems, according to anexample embodiment.

FIG. 16 gives a 3-d view of the load layer with each stem connected to apreload spring, according to an example embodiment.

FIG. 17 gives a close up view of the preload stems supported by a seriesof springs to cause deflection under an externally applied load onto thecarrier pad, according to an example embodiment.

FIG. 18 shows a polishing pad (with or without abrasives) attached tothe stem ends spring loaded and attached to a carrier pad, according toan example embodiment.

FIG. 19 gives an exploded view polishing pad (with or without abrasives)attached to the stem ends spring loaded and attached to a carrier pad,according to an example embodiment.

FIG. 20 gives a cross section of a CPP concept with individual pads orabrasives attached to the ends of load stems, according to an exampleembodiment.

FIG. 21 gives a close up view of the preload stems supporting polishingpads or abrasive elements, according to an example embodiment.

FIG. 22 gives a cross section of a CPP concept with individual polishingpads or abrasive elements supported by a revolute or cylindrical joint,according to an example embodiment.

FIG. 23 gives a cross section of a CPP concept with polishing padssupported by a revolute or cylindrical joint, according to an exampleembodiment.

FIG. 24 gives a close up view of the preload stems with an end revolutejoint connected to a supporting pad, according to an example embodiment.

FIG. 25 gives a polishing pad arrangement with individual pad connectedthough a non-straight link, according to an example embodiment.

FIG. 26 gives an exploded view of the polishing pad arrangement shown inFIG. 25, according to an example embodiment.

DETAILED DESCRIPTION

Described herein is a pad suitable in a variety of CMP processes. Aplurality of independently suspended polishing pads 401 are assembledinto a polishing article 400 referred to as composite polishing pad(CPP). Each polishing pad is suspended to a pressure pad 402 attached toa flexure 403 and subject to a substantially constant preload. Thepreload is applied through a stem end 406 referred to as dimple actingon the opposite side of the flexure suspending the polishing pad. Eachpolishing pad applies a substantially constant pressure via the stemindependently of its location on the semiconductor wafer. The suspendedpolishing pad follows the contour of the semiconductor wafer regardlessof the waviness of the semiconductor wafer. The preload apparatus isformed of a stem 406 attached to a spring mechanism 407 allowingsubstantially constant load as a function of vertical displacement. Theability of each polishing pad to comply in the plane of the wafer andfollow the wafer runnout causes substantially uniform material removal.

In one embodiment, a series of independent pressure pads 602 attached toindependent stems 603 supported by preload flexures. In turn thepolishing pads attached to the pressure allowing substantially constantload as a function of vertical displacement during polishing. Theability of each pressure pad to comply vertically with respect to planeof the wafer assures a constant pressure at each pressure pad 602.

In one embodiment, a series of independent pressure pads 802 attachedvia a spherical joints 803 to independent stems 804 supported to preloadspring flexures 805. The flexures 805 deflect under a normal load to thepressure pads. In turn the polishing pads attached to the pressure padallow substantially constant load as a function of vertical displacementduring polishing. The ability of each polishing pad to comply in thevertical direction of the wafer and in the plane of wafer assures aconstant pressure at each pressure pad independently of the waferwaviness and runnout.

In one embodiment of the present invention, the pressure applied by eachpolishing is made variable from inner diameter to outer diameter tocause uniform material removal throughout the semiconductor wafer as thetravel contact length of each polishing pad is not constant from innerdiameter to outer diameter. For example, the outer polishing pads can beenvisioned to have a larger preload to apply a larger pressure in orderto remove more material. The polishing pad may also include polishingfluid or slurry distribution layer.

The present invention recognizes the importance of tailored polishingpressure to maintain a uniform polishing action. Fragile low-K materialscan be easily damaged by high stresses resulting from polishingoperations. Nucleation of failure sites can occur at local high-pressurespots. A constant pressure pad configured according to the presentinvention provides the necessary information to develop polishingprocesses which do not exceed critical stress levels during processingoperations. Designing the preload spring to yield a constant preload isa strategy to achieve uniform pressure to maintain a uniform polishingaction.

In some embodiments of the present invention, the polishing pad may beconfigured to apply a higher pressure at a specific location or avariable pressure at various radii of the semiconductor wafer. Forexample, the polishing pads can be made of various materials such aspolyurethane, polyester, polycarbonate, delrin, etc. In varyingembodiments of the present invention, polishing elements are made of anysuitable material such as polymer, metal, ceramic or combination thereofand capable of movement in the vertical axis and complying to thesemiconductor wafer topography. Alternatively, or in addition, thepolishing elements may be made in composite structures where a core ismade of one material and the shell is made of another material (e.g.,one of which is transparent or conductive). For example, a polishingelement may contain a core made of a conductive material such asgraphite or conductive polymer.

Pressure control during polishing is critical especially for nanometerfeature sizes. Table 1 shows the decrease in required pressure as afunction of material type and die feature size.

FIG. 4 depicts a cross section of one embodiment of the presentinvention. A first adhesive layer 408 is applied to a backing element409 supporting a preload flexure consisting of a stem protruding fromthe base 411 and in contact with a pivoting flexure supporting thepolishing pad 403. An adhesive layer 404 holds the preload 411 anddimple structure 406 attached to the backing layer 409. An opening ismade in the backing layer beneath the preload fixture to allow for thedeformation of the preload flexure 411 without interference during thepressure generation during the polishing process. A series of protrudingpillars 405 provide a fixed boundary condition supporting the outeredges of the pivoting flexure. Finally the abrasives 401 are attached tothe pressure pads 402.

FIG. 5 is an exploded view of a single polishing pad assembly 420contained in the CPP concept. A backing layer 409 with an opening 414with an opening is assembled via an adhesive layer 408 to a preloadflexure 407. The preload fixture has a preload stem 406 attached to apreload flexure design 407 capable of imparting a substantially constantpreload for example. A series of protruding pillars 405 provide supportto the pivoting flexures 403 supporting the pressure pads 401. Theembodiment disclosed allows for the pressure pads 401 to follow thesemiconductor wafer topography while allowing a locally stiff padcapable of planarazing the wafer.

FIG. 6 shows a series of individually suspended and preloaded polishingelements 401 assembled in a polishing pad referred to as CPP. A backingelement 409 supports the preload flexure 411 applying a substantiallyconstant load if desired. It is therefore the case that the proposedpolishing pad design does not require a trade-off between WIWNU andplanarization characteristics of the pads. This lack of requiredtrade-off has led to the development of polishing pads (CPP) acceptablefor processing dielectric layers (such as silicon dioxide) and metalssuch as tungsten (which is used for via interconnects in subtractiveprocessing schemes). Avoiding over polishing in copper processing isachieved by CPP.

An exploded view is offered in FIG. 7 shows the various componentsinvolved in fabricating a composite universal polishing pad (CPP). It isforeseen that the backing layer 409 is attached to the preload flexurelayer 411, followed by the attachment of the pivoting flexure layer 403and finally the polishing pads 401 (CMP pads or abrasive pads) arefinally added as the last step of the process.

A close up view in FIG. 8 offers a view of the assembly of eachindependent polishing structure 401. Note that the preload stem 406 ispressed against the pivoting flexure 407 allowing the polishing pad tomove in the vertical direction while complying to the semiconductorwafer. Such strategy allows for the use of a hard polishing pad whileproviding compliance at the interface of the semiconductor wafer. Thisstrategy of decoupling the pad characteristics from its ability tocomply at the semiconductor interface leads to removing the traditionaltrade-off between WIWNU and planarization characteristics of the pads.

Detailed view of the pivoting flexure is provided in FIG. 9 includes aseries of curvilinear springs 407 organized to allow compliant motionwith respect to the semiconductor wafer of the attached polishing pad orpolishing abrasive element 401. The springs 407 have a curvilinear shapedesigned to allow for out of plane motion while allowing for substantialpivoting to follow the plane defined by the semi-conductor wafer; notethat straight springs do not flex out of plane causing tensile stressesin the spring beams and are inadequate. The spring members must allowfor compliance out of plane under a normal load. Various examples ofspring members can be listed such as L-shaped and Z-shaped.

The preload flexure layer is shown in details in FIG. 10. The preloadstem 406 shows a spherical end to allow a dimple 413 like contact withthe pivoting structure. A preload flexure 407 deforms under a preloadapplied by the stem 406. A series of protruding pillars provide 405support to the ends of the pivoting flexure not shown herein. Thepreload stem can have many embodiments such as flat top, spherical andcylindrical structures.

FIG. 11 gives a cross section of a CPP concept with a continuousflexible polishing pad 501 attached to the contact pads 502 of eachpivoting flexure 503. Upon bringing the CPP in contact with wafer apreload is generated from the preload flexure 507 to the contacting pads503 by deflecting the supporting springs 507. The dimple end of thestems 515 contacts the back end of the pivoting flexure 503. The preloadflexure 508 applies a constant load onto the contact pads 502.

FIG. 12 gives an exploded view of a polishing pad assembly contained inthe CPP. A backing plate 509 is assembled via an adhesive layer 508 to apreload flexure 507. The preload fixture has a preload stem attached toa spring flexure design capable of imparting a substantially constantpreload for example. A series of protruding pillars provide support tothe pivoting flexures. A final layer of continuous polishing pad 501 isassembled to the individual contacting pads 502 to provide constantpreload at each contacting pad during the polishing process. Theembodiment disclosed allows the continuous polishing pad to follow thesemiconductor wafer topography while allowing a locally stiff padcapable of planarazing the wafer.

The preload flexure layer is shown in details in FIG. 13. The preloadstem shows dimple structure like in contact with the gimballingstructure. A preload flexure deforms under a preload applied by thecontacting pad 502 contacting the polishing pad 501. A series ofprotruding pillars provide supports to the ends of the pivoting springs503. The preload stem can have many embodiments such as flat top,spherical and cylindrical shapes. The contact pad presses against thecontinuous polishing pad to provide a substantially uniform pressure.

FIG. 14 gives an exploded view of the assembly shown in FIG. 13. Apolishing pad 501 is in direct contact with a pressure pad 502 supportedby a pivoting flexure 504. The pivoting flexure 504 is preloaded via thedimple 503 attached to the spring loaded stem 503.

FIG. 15 gives a cross section of a CPP concept with a continuouspolishing pad 601 at the end of the contacting pads 602. Upon bringingthe CPP in contact with wafer a preload is applied to the polishing pad601 by deflecting the supporting springs 604. The preload springs applya constant load onto the polishing pad 601.

FIG. 16 shows a series of pressure pads 602 organized to form a circularpad 605. Each pressure pad 602 is attached to spring structure 604allowing for compliance in the vertical direction. The preload fixture604 has a preload stem attached to a spring flexure design capable ofimparting a substantially constant preload for example. The embodimentdisclosed allows the continuous polishing pad to apply a substantiallyconstant load on the semiconductor wafer while allowing a locally stiffpad capable of planarazing the wafer.

The preload flexure layer 605 is shown in details in FIG. 17. The end ofthe preload stem 603 holds a pressure pad 602. A preload flexure 604deforms under a load applied by the pressure pads 602. The pressure padpushes against the continuous polishing pad to provide a substantiallyuniform pressure.

FIG. 19 gives an exploded view of the assembly shown in FIG. 18. Apolishing pad 601 is in direct contact with a multitude of pressure pads602 supported by a backing layer 605.

FIG. 20 gives a cross section of a polishing pad with a series ofindependent flexible pressure pads 703 at the end of the load stems 705.The end of each pressure pad 702 is equipped with abrasive pads 701 or apolishing pads 701. Each individual polishing pad or abrasive paddeflects under an externally applied load to provide a substantiallyconstant pressure upon contact with the wafer. The preload springs 703apply a constant load onto the polishing pad.

FIG. 21 shows a series of pressure pads 702 organized to form a circularpad 700. Each pressure pad 702 is attached to spring structure 703allowing for compliance in the vertical direction with respect to thewafer. The preload fixture 703 is equipped with a preload stem 705attached to a spring flexure design 703 capable of imparting asubstantially constant preload for example. The embodiment disclosedallows the continuous polishing pad to apply a substantially constantload on the semiconductor wafer while allowing a locally stiff padcapable of planarazing the wafer.

FIG. 22 shows a concept of a polishing pad 800 where the pressure pad802 is suspended by a revolute joint 803 to the load stem 804. The loadstem 804 is supported by a series of springs 805 design to deflect undera normal load. The pressure pad 804 is equipped with an abrasive orpolishing pad 801. The configuration shown herein allows for thepolishing pad or abrasive pad to follow the wafer topography with 3dimensional rotational freedoms. The rotary joint allows the polishingpad to pivot with respect to the wafer.

FIG. 23 shows a concept where the pressure pad is suspended by arevolute joint to the load stem. The load stem is supported by a seriesof springs design to deflect under a normal load. The pressure padssupport a continuous polishing pad. The configuration shown hereinallows for the polishing pad to follow the wafer topography with 3dimensional rotational freedoms at each pressure pad.

FIG. 24 gives a detailed view of a single pressure pad 802. A revolutejoint 803 between the load stem 804 and the pressure pad 802 supportsthe pressure pad. The load stem is supported by a series of verticallycompliant springs 805 allowing the pressure pad 802 to freely pivot withrespect to the surface of the wafer while keeping the ability to followthe runnout produced by the wafer.

FIG. 25 gives a detailed view of a polishing pad 900 used in conjunctionwith the present invention. The polishing pad assembly 910 is fabricatedvia an S-shaped link 920 to each others. The S-shaped links are arrangedto connect each polishing pad with minimal out of plane resistance andcontributes to decoupling the motion of each polishing pad from eachother. Cross talk between polishing pads is minimized for example ifpolishing pad 910 is deflected in the z plane perpendicular to thepolishing pad assembly 910, the displacement experienced by thesurrounding pads 911, 912, 913, and 914 will be minimum. FIG. 26 gives adetailed view of a polishing pad 900 used in conjunction with thepresent invention showing the S-structure of the links and the polishingpads. The S-shape feature 920 has a low bending stiffness due to S shapeallowing minimum cross talk between the pads when subjected to anin-plane or out of plane deflection. Non-straight shaped links such asZ, L, etc. can be arranged to further reduce the bending moment. Incontrast, a straight connector generates tension on the adjacentpolishing pads during a vertical or in-plane motion. Displacement due toin plane stretching of a straight connector requires very large forcesto be produced thus limiting the amount of vertical displacement orin-plane displacement achieved by traditional configurations as shown incontinuous polishing pad (601). So instead of fabricating a continuouspolishing pad a discontinuous sheet with S shape connector attachingadjacent independent pads is desirable for ease of assembly and forproviding a low coupling between individual polishing pads. Such pad canbe used to accept CMP polishing pads, abrasive charged polishing pads,etc.

Useful adhesives include, e.g., pressure sensitive adhesives, hot meltadhesives and glue. Suitable pressure sensitive adhesives include a widevariety of pressure sensitive adhesives including, e.g., naturalrubber-based adhesives, (meth)acrylate polymers and copolymers, AB orABA block copolymers of thermoplastic rubbers, e.g., styrene/butadieneor styrene/isoprene block copolymers available under the tradedesignation KRATON (Shell Chemical Co., Houston, Tex.) or polyolefins.Suitable hot melt adhesives include, e.g., polyester, ethylene vinylacetate (EVA), polyamides, epoxies, and combinations thereof. Theadhesive preferably has sufficient cohesive strength and peel resistanceto maintain the components of the fixed abrasive article in fixedrelation to each other during use and is resistant to chemicaldegradation under conditions of use.

Examples of useful commercially available backing, materials includepoly(ethylene-co-vinyl acetate) foams available under the tradedesignations 3M SCOTCH brand CUSHIONMOUNT Plate Mounting Tape 949double-coated high density elastomeric foam tape (Minnesota Mining andManufacturing Company, St. Paul, Minn.), EO EVA foam (Voltek, Lawrence,Mass.), EMR 1025 polyethylene foam (Sentinel Products, Hyannis, N.J.),HD200 polyurethane foam (Illbruck, Inc. Minneapolis, Minn.), MC8000 andMC8000EVA foams (Sentinel Products), SUBA IV Impregnated Nonwoven(Rodel, Inc., Newark, Del.).

Thus, an improved fixed abrasive or CMP polishing pad and process forpolishing semiconductor wafers and structures layered thereon has beendescribed. Although the present polishing pad and processes for using ithave been discussed with reference to certain illustrated examples, itshould be remembered that the scope of the present invention should notbe limited by such examples.

In one aspect, the invention features an abrasive article including a) afixed abrasive element including a plurality of abrasive particles, b)the fixed abrasives are affixed to a gimballing flexure, (c) a gimbalstructure formed around the fixed abrasive elements hold the abrasiveelement, (d) a stem supported by a preload flexures applies a loadthrough a dimple to back of the gimballing flexure, (e) a plurality ofpillars affixed to the preload flexure layer provide fixed boundaryconditions for the edges of gimbal flexure, and (f) an opening made inthe carrier allows for the preload flexure to move vertically with nointerference.

In some embodiment, the invention features an abrasive article including(a) a fixed abrasive element including a plurality of abrasiveparticles, (b) the fixed abrasives are affixed to a pressure pad, and(c) a stem supported by a preload flexure applies a load to the pressurepad under normal deflection.

In some embodiment, the invention features an abrasive article including(a) a polishing pad, (b) the polishing pad is affixed to a pressure pad,and (c) a stem supported by a preload flexure applies a load to thepressure pad under normal deflection.

In some embodiment, the invention features an abrasive article including(a) a fixed abrasive element including a plurality of abrasiveparticles, (b) the fixed abrasives are affixed to a pressure pad, (c)the pressure pads are supported by a revolute joint to (d) a stemsupported by a preload flexure applies a load to the pressure pad undernormal deflection.

In some embodiment, the invention features a polishing pad (a) apolishing pad, (b) the polishing pad is supported by a spherical jointto (c) a stem supported by a preload flexure applies a load to thepressure pad under normal deflection.

In some embodiments polishing pads replace the abrasive articles. Thepads interact with slurries to provide a CMP operation as describedpreviously. The pad geometry is typically flat of shaped to enhanceinteraction with the slurry.

In other embodiments fluid bearing structures are formed on the fixedabrasive structures or the soft pad structures to allow for a liftbetween the lubricant present during polishing and the semiconductorwafer. Such fluid bearing forms during the relative motion of thecomposite polishing pad and the semiconductor wafer due to the shearingof the lubricant.

In other embodiments the gimbal flexure allows the fixed abrasiveelement of the pads to follow the semiconductor wafer topography andexerts a uniform pressure. The gimbal flexure is fabricated from apolymer or stainless steel material. The gimbal structure allows uniformplanar stiffness of the abrasive element or the pads to enable followingthe contour of the semiconductor wafer.

In other embodiments the preload stem dimple structure applies a givenpreload onto each abrasive element or pad. The geometry of the loaddimple structure is designed such that the end of the load dimplestructure is spherical and allows for contact against resilient element.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which these inventions belong. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present inventions, the preferredmethods and materials are now described. All patents and publicationsmentioned herein, including those cited in the Background of theapplication, are hereby incorporated by reference to disclose anddescribed the methods and/or materials in connection with which thepublications are cited.

The publications discussed herein are provided solely for theirdisclosure prior to the filing date of the present application. Nothingherein is to be construed as an admission that the present inventionsare not entitled to antedate such publication by virtue of priorinvention. Further, the dates of publication provided may be differentfrom the actual publication dates which may need to be independentlyconfirmed.

Other embodiments of the invention are possible. Although thedescription above contains much specificity, these should not beconstrued as limiting the scope of the invention, but as merelyproviding illustrations of some of the presently preferred embodimentsof this invention. It is also contemplated that various combinations orsub-combinations of the specific features and aspects of the embodimentsmay be made and still fall within the scope of the inventions. It shouldbe understood that various features and aspects of the disclosedembodiments can be combined with or substituted for one another in orderto form varying modes of the disclosed inventions. Thus, it is intendedthat the scope of at least some of the present inventions hereindisclosed should not be limited by the particular disclosed embodimentsdescribed above.

Thus the scope of this invention should be determined by the appendedclaims and their legal equivalents. Therefore, it will be appreciatedthat the scope of the present invention fully encompasses otherembodiments which may become obvious to those skilled in the art, andthat the scope of the present invention is accordingly to be limited bynothing other than the appended claims, in which reference to an elementin the singular is not intended to mean “one and only one” unlessexplicitly so stated, but rather “one or more.” All structural,chemical, and functional equivalents to the elements of theabove-described preferred embodiment that are known to those of ordinaryskill in the art are expressly incorporated herein by reference and areintended to be encompassed by the present claims. Moreover, it is notnecessary for a device or method to address each and every problem oughtto be solved by the present invention, for it to be encompassed by thepresent claims. Furthermore, no element, component, or method step inthe present disclosure is intended to be dedicated to the publicregardless of whether the element, component, or method step isexplicitly recited in the claims.

1. A polishing pad comprising: an abrasive element; a pivoting flexureformed around the abrasive element and attached to the abrasive element,the abrasive element including a plurality of abrasive particles, thepivoting flexure including a dimple to allow pivoting of the abrasiveelement; (d) a stem supported by a preload flexure, the stem positionedto apply a load through the dimple of the pivoting flexure, (e) aplurality of pillars affixed to a plurality of preload flexures arrangedin a layer to provide fixed boundary conditions for the edges ofpivoting flexure, and (f) an opening made in the carrier that allows forthe preload flexure to move vertically.
 2. The polishing pad of claim 1,wherein the fixed abrasive elements are in a rectangular shape.
 3. Thepolishing pad of claim 1, wherein the fixed abrasive elements are in acircular shape
 4. A polishing pad comprising: a polishing pad, apivoting flexure formed around the polishing pads hold the polishingpads, the polishing pad affixed to pivoting flexure, a stem supported bya preload flexure, the stem applying a load through a dimple pn thepivoting flexure, a plurality of pillars affixed to a preload flexurelayer to provide fixed boundary conditions for the edges of pivotingflexure, and an opening made in the carrier allows for the preloadflexure to move vertically with substantially no interference.
 5. Thepolishing pad of claim 4, wherein the polishing pad is one of aplurality of polishing pads arranged in a rectangular shape.
 6. Thepolishing pad of claim 4, wherein the polishing pad is one of aplurality of polishing pads arranged in a circular shape.
 7. A polishingcomprising a) a polishing pad element, b) the polishing pad elements areaffixed to a pivoting flexure, (c) a pivoting flexure formed around thefixed abrasive elements hold the abrasive element, (d) a stem supportedby a preload flexure to apply a load through a dimple on the pivotingflexure, (e) a plurality of pillars affixed to the preload flexure layerprovide fixed boundary conditions for the edges of pivoting flexure, and(f) an opening made in the carrier allows for the preload flexure tomove vertically with substantially no interference.
 8. The polishing padof claim 7, wherein the polishing pad is one of a plurality of polishingpads arranged in a rectangular shape.
 9. The polishing pad of claim 7,wherein the polishing pad is one of a plurality of polishing padsarranged in a circular shape.
 10. The polishing pad of claim 7, whereinthe polishing pad is one of a plurality of polishing pads arranged in arectangular shape.
 11. The polishing pad of claim 7, wherein thepolishing pad is one of a plurality of polishing pads arranged in acircular shape.
 12. The polishing pad of claim 7, wherein at least oneof the polishing pads is fabricated for chemical mechanical polishing(CMP) applications.
 13. The polishing pad of claim 7, wherein at leaston of the polishing pads contains abrasive particles.
 14. A polishingpad, comprising: a plurality of flexible flexures with flexibility in adirection transverse to the plane defined by the polishing plane, and aplurality of polishing elements each attached via stems to a theflexible flexures applying a desired pressure in the transversedirection with respect to the polishing pad in order to contact andpolish the workpiece.
 15. The pad of claim 17, wherein at least one ofthe polishing elements has a circular cross sections.
 16. The pad ofclaim 17, wherein at least one of the polishing elements has arectangular cross sections.
 17. A polishing pad, comprising: a pluralityof flexible flexures with flexibility in a substantially verticaldirection to the plane defined by the polishing plane, and a pluralityof pressure pads each connected via spherical joints to the stemsattached to the pivoting flexures applying a desired pressure in avertical direction with respect to the polishing pad in order to contactand polish the workpiece.
 18. The polishing pad of claim 17, wherein atleast one of the polishing elements has circular cross sections.
 19. Thepolishing pad of claim 17, wherein at least one of the polishingelements has rectangular cross sections.
 20. A polishing pad comprising:a plurality of individual polishing pads, and at least one in-plane nonstraight links connecting adjacent polishing pads.
 21. The polishing padof claim 20, wherein the polishing pads are in a rectangular shape. 22.The polishing pad of claim 20, wherein the polishing pads are in acircular shape.
 23. The polishing pad of claim 20, wherein at least onof the polishing pads is fabricated for CMP applications.
 24. Thepolishing pad of claim 20, wherein at least on of the polishing padscontains abrasive particles.
 25. The polishing pad of claim 20, whereinat least on of the polishing pads is textured and substantially coveredwith a deposited film, such as diamond like carbon (DLC).